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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

A study of Eye-tracking properties utilizing Tobii Eye Tracker 5

Rahman, Muhammad Mezanur January 2022 (has links)
Eye-tracking is the process of determining the point where the viewer is looking at. Therefore, an eye tracker is a device that measures eye positions and eye movements. Over the recent few years, eye trackers are being used in research in the area of medical technology, visual system, rehabilitation, and human-computer interaction. This study explores the application of eye-tracking in watching and rendering images on a computer screen. In this research, Eye-tracker 5 developed by Tobii is used which is a popular instrument among other eye trackers. Tobii Eye Tracker 5 includes a software development kit (SDK) enabling the creation of new research projects based on eye-tracking and head movement. This work measured eye-tracking streaming data on the digital images, and post-process the gaze data to observe the gaze pattern of the human eye. This thesis investigated the impact of blinking using subtle gaze direction (SGD) approach, which states that flickering on the computer screen in peripheral vision instead of foveal vision attracts human attention and as the viewer’s foveal vision attracted to that blinking point, flickering was stopped and, subsequently, performed flickering to the next point of interest while the viewer is watching the previous point of interest. The work successfully modeled flickering on the desired locations of an image. Furthermore, rendering to different images is also demonstrated in this work using entirely through eye movement. It is envisaged that eye-gazing-based control technology would have tremendous applications in almost all areas of future technology, particularly in assistive technology.
22

Determination of Salient Design Elements Through Eye Movements, Aesthetics, and Usability

Asuncion, Bryan C 14 December 2018 (has links)
The goal of study 1 was to use a remote eye tracker to understand how eye movements change with 7 geometrically varied remote controls to determine design element saliency. 20 participants were used to measure the following eye metrics: number of fixations prior to first fixation of any AOI, time to first fixation of an AOI, number of fixations on an AOI, dwell time of the first fixation on an AOI, total dwell time of an AOI, and the percentage of time spent on an AOI. The results of the study showed that all participants spent between 75-85% of their time fixated on the button layout which was not defined as an AOI. No statistical differences were found in the values measured for all eye tracking metrics across similarly defined AOIs. In study 2, the objective was to determine attitudes towards appearance and usability of the 7 remote control designs using the participants from study 1. Participants were asked to rate their attitudes and preferences, using a Likert-based questionnaire, about the qualities of appearance and usability for the attributes of proportion, shape, and configuration. They were asked open-ended questions about their likes and dislikes regarding the qualities of appearance and usability. Lastly, participants were given a pairwise comparison survey where they chose their preferred remote design, based on appearance, for 10 paired sets of contrasting remote designs. The hourglass subjacent and hourglass round designs were rated highest for appearance and usability from the Likert questionnaire. The hourglass round design was ranked highest for the pairwise comparison survey. For study 3, the goal was to determine attitudes towards appearance and usability of the 7 remote designs with online participants. 300 participants were asked to rate their attitudes and preferences using the same Likert-based questionnaire from study 2. They were asked the same open-ended questions and administered the same pairwise comparison survey as in study 2. The results of the Likert questionnaire showed that the hourglass subjacent and hourglass round designs were rated highest for appearance and usability. From the pairwise comparison survey, the hourglass round design was ranked the highest.
23

Integration of eye tracking device and 3D motion capture for simultaneous gaze and body movement analysis / Integrering av ögonspårningsenhet och 3D-rörelsefångst för samtidig blick-och kroppsrörelseanalys

Narasappa, Deepa January 2022 (has links)
The purpose of this project was to analyze the coordination between gaze and the upper limb movement while performing a predefined task. We implemented a method to simultaneously compute and visualize recorded gaze data from a head mounted eye tracker and motion data from a motion capture system in the same coordinate system.  A python script was implemented to temporarily synchronize the two systems and then proceed with the spatial/coordinate transformation which was validated with the data acquired while the subject was asked to perform specific tasks. Task 1 was to fixate his gaze on a block placed in the center of a table and the Task 2 was to stack the blocks by picking it up and placing it on top of each other. Wrist and elbow flexion-extension angles were tracked simultaneously based on reflective markers trajectories while performing the task. This was visualized and discussed on how the results of our study suggest that the eye movements play a vital role in planning, estimating, coordinating and providing feedback for the body to perform a motor task.
24

Gaze Pattern and Motion Control During Walking While Multitasking / Blickmönster och rörelsekontroll vid gång med samtidig multitasking

Karlsson, Filip January 2023 (has links)
In Sweden almost three persons over the age of 65 years dies every daybecause of fall injuries. The overall societal costs of elderly fall accidentswere estimated to to be 14 billion SEK, and if no action is taken this cost isestimated to increase to 22 billion SEK until 2050. The individual decreasein life of quality due to pain, decrease of independence and, for those stillworking, a decrease in income is of course also well worth considering.It is well known that multitasking while walking will decrease attentionon the surroundings and gait behaviour which increases the risk of falling. Itis known that walking uses both sensory input and visual inputs to guide themotion. The visual input prepares the body to adjust itself before a step istaken to optimize the outcome.This study aimed to investigate the effect of multitasking on gaze strategiesand gait performance. Five healthy adults walked over a setup of ramps and astep while performing three different levels of cognitive loading: just walking,walking and performing mental arithmetic’s and walking and scrolling on amobile cell phone.The eye tracking device Pupil Core (Pupil Labs, Berlin, Germany) wasused to capture the gaze points of the participants and Vicon Nexus togetherwith force plates were used to capture data to compute the kinematics of theparticipants during the walking.The results revealed that four out of four participants had a lower ratio ofgaze fixations on objects of interest when scrolling on the phone comparedto just walking, and three out of four participants had a lower ratio of gazefixations on objects of interest when doing mental arithmetic’s compared tojust walking. Simultaneously the gait parameters and kinematics changed in away that might increase the risk of falling. Four out of four participants had adecrease in average stride length and average stride velocity when walkingwhile scrolling on a phone and a decrease in average stride velocity whenperforming mental arithmetic’s compared to just walking. Three out of fourparticipants had a decrease in average stride length when performing mentalarithmetic’s compared to just walking.Since the participant number was low more studies are needed to confirmthese results. The experimental design would benefit from adjustments to tryto separate the effect on gaze behaviour between altered cognitive loading andaltered gait pattern, but are a good base to use for further studies.
25

Validation d’une vidéo d’animation pour l’évaluation visuelle de l’hémianopsie homonyme

Ferreri, Jeff 08 1900 (has links)
Mémoire de maîtrise présenté en vue de l'obtention de la maîtrise en psychologie (M. Sc) / Contexte : L’hémianopsie homonyme (HH) a un impact significatif sur les activités quotidiennes, et les méthodes actuelles d’évaluation des personnes ayant une amputation du champ visuel ne permettent pas de combiner l’évaluation de la vision centrale et périphérique. Objectifs : Cette étude visait à valider un film d’animation innovant comme nouvel outil d’évaluation pour mesurer l’étendue du champ visuel aveugle, à établir une norme auprès d’une population contrôle en bonne santé visuelle et à déterminer le niveau de faisabilité du test. Méthodologie : La vidéo d’animation présentait une série de personnages à détecter. Elle était présentée sur 160° répartis sur 3 moniteurs d’ordinateur. Un eye-tracker était utilisé pour vérifier la stabilisation de la tête et le contrôle de la fixation. Quarante participants en bonne santé, âgés de 18 à 75 ans, ont été recrutés. Résultats : La plupart des animations ont été perçues par des participants contrôle sains, ce qui a permis d’établir une norme pour le test. Concernant l’appréciation du test, 60 % des participants l’ont beaucoup apprécié, 29 % l’ont aimé et 11 % ont eu une opinion neutre. Conclusion : Cet outil écologique évalue simultanément la vision centrale et la vision périphérique à l’aide d’un film d’animation. Avec des normes établies à partir d’une population générale ayant une vision saine et un accueil positif des participants, cet outil pourrait être utilisé pour évaluer et dépister les personnes suspectées d’avoir une HH, en particulier chez les enfants. / Background: Homonymous hemianopia (HH) has a significant impact on daily activities, and current methods of assessing people with visual field amputation don’t combine assessment of central and peripheral vision. Objectives: The aim of this study was to validate an innovative animated film as a new assessment tool for measuring the extent of the blind visual field, to establish a standard in a visually healthy control population, and to determine the test’s feasibility. Methodology: The animated video presented a series of characters that needed to be detected. It was presented in 160 degrees on 3 computer monitors. An eye tracker was used to check head stabilization and fixation control. Forty healthy participants aged between 18 and 75 were recruited. Results: Most of the animations were perceived by healthy control participants, helping to establish a standard for the test. In terms of appreciation of the test, 60% of participants liked it a lot, 29% liked it and 11% had a neutral opinion. Conclusion: This ecological tool simultaneously assesses central and peripheral vision using an animated film. With standards based on a general population with healthy vision and a positive reception from participants, this tool could be used to assess and screen people suspected of having HH, particularly in children.
26

Look2Hook - A Comparative Study of Eye-tracker and Mouse Based Object Selection in a Complex Environment / Look2Hook - En Komparativ Studie av Eye-tracker och Musbaserad Objekt Selektion i en Komplex Miljö

Erlandsson, Oskar January 2021 (has links)
In this thesis the Tobii eye-tracker 4L was used to investigate how well eye-tracking solutions such as a confirmation-click and dwell-time algorithm compares to the standard mouse input device when performing selection tasks in a map environment. In order to distinguish the different complexity one could face, two user cases are proposed. Scenario one includes non clustered objects. Scenario two include clustered occluded objects. A user study with nine different participants where conducted in order to compare the execution times and find out how error prone the different methods were. Each test participant performed eight different tests, three in the non-clustered scenario and five in the clustered scenario. In two of the tests in the clustered scenario test participants were aided with zooming through a zoom algorithm. The methods was evaluated by calculating the average execution times and errors along with the corresponding standard deviations. In order to grasp the users experience a subjective cognitive load score was calculated with the help of a questionnaire. The eye-tracker methods was found to be competitive in comparison to mouse interaction in the more simple non-clustered case. However, in a more complex scenario such as the clustered case the mouse interaction had the lowest average completion time and cognitive load score. A different type of selection behaviour was discovered among the test participants in the clustered scenario due to the difference in precision between the eye-tracker and mouse interaction. Finally interesting areas to consider in the future is presented and discussed. / I denna avhandling användes en Tobii eye-tracker 4L för att undersöka hur väl eye-tracking metoder så som en bekräftelseklick och dwell-time algoritm jämför sig med standard mus interaktion vid objekt selektion i en kartmiljö. För att urskilja variationen i komplexitet man kan möta föreslås två olika användarfall. Scenario ett inkluderar objekt som är distinktivt separerade och därav ej grupperade. Scenario två inkluderar grupperade samt ockluderade objekt. En användarstudie med nio olika deltagare genomfördes för att jämföra exekveringstiderna och ta reda på hur felbenägna de olika metoderna var. Varje testdeltagare utförde åtta olika tester, tre i det icke-grupperade scenariot och fem i det grupperade scenariot. I två av testerna i det grupperade scenariot fick deltagarna hjälp med att zooma genom en zoomalgoritm. Metoderna utvärderades genom att beräkna de genomsnittliga exekveringstiderna samt antal fel tillsammans med motsvarande standardavvikelser. För att förstå hur användarna upplevde de olika metoderna togs en subjektiv kognitiv belastningspoäng fram genom ett frågeformulär. Eye-tracker metoderna var konkurrenskraftiga i jämförelse med musinteraktion i det enklare fallet där objekt ej var grupperade. I ett mer komplext scenario, såsom i det grupperade fallet, hade dock musinteraktionen den lägsta genomsnittliga exekveringstiden och kognitiva belastningspoängen. En annan typ av selektions beteende upptäcktes bland testdeltagarna i det grupperade scenariot på grund av skillnaden i precision mellan eye-trackern och musinteraktionen. Slutligen presenteras och diskuteras intressanta områden att överväga vid framtida arbeten.
27

Odpověď zrakového analyzátoru při řízení vozidla v reálných podmínkách a na simulátoru při paralelní motorické úloze. / The response of the visual system when driving a car in real conditions and in a simulator during a parallel motor task.

Čiháková, Lucie January 2011 (has links)
Work title: The response of the visual system when driving a car in real conditions and in a simulator during a parallel motor task. Aims: To implement a laboratory measurement in a driving simulator and in real conditions during a parallel motor task. To track the response of the visual system during the task and to determine potential differences in the response of the visual system and in the speed in the simulator and in the real car environment. Methods: The laboratory measurement was realized in a driving simulator OCTAVIA II. The measurement in real conditions was realized in Škoda Octavia as well. The eye-tracking method was used to track the drivers` eyes. Results: In the simulator the more experienced driver managed to do the parallel motor task within a shorter period of time than the less experienced driver, lower frequency of looks at the radio during the tasks with the more experienced driver was not proved. There was not an evidence of more balanced speed during the drive with the more experienced driver in the simulator. On the average the driver spent shorter time doing the tasks in the real environment than in the simulator and the total number of looks at the radio was lower. The speed of the drive in the real environment was lower than the speed in the simulator. Key words:...
28

Investigação experimental do Kindchenschema lorenziano: Preferência visual de portadores de Síndrome de Williams e Transtorno do Espectro Autista em resposta a imagens neotênicas faciais / Experimental investigation of the lorenzian Kindchenschema: visual preference of Williams Syndrome patients and Autistic Spectrum Disorder in response to neotenic facial images

Carvalho, André Paulo Correa de 11 December 2018 (has links)
A neotenia é um importante processo biológico-evolutivo que conserva traços fenotípicos do jovem no indivíduo adulto. A neotenia modifica a velocidade típica da ontogênese das características morfológicas compartilhadas pelos ancestrais. Essas mudanças podem representar oportunidades de mudanças fenotípicas dramáticas com poucas alterações genéticas, possibilitando alterações de estados especializados. O etólogo Konrad Lorenz reconheceu características neotênicas em humanos e algumas espécies de mamíferos na fórmula estrutural do corpo (principalmente da face) típica de infantes. Essa fórmula corpórea foi batizada por Lorenz de Kindchenschema. Os humanos típicos respondem quando observam traços infantis ativando uma resposta chamada de Efeito Kindchenschema (EK). Neste efeito verifica-se uma diminuição da agressividade, estimulação do cuidado parental e engajamento social. São raros os trabalhos de escaneamento do olhar em portadores de disfunções do neurodesenvolvimento, como a Síndrome de Williams (SW) e o Transtorno do Espectro Autista (TEA). O presente trabalho é o primeiro na literatura a investigar o escaneamento do olhar em portadores de SW e TEA usando estímulos faciais neotênicos de humanos e animais. Na presente investigação foram estudados 21 portadores de SW e 25 portadores de TEA, o grupo controle (GC) contou com 33 participantes. Encontramos uma correspondência entre os resultados declarados do estímulo preferido e o tempo de fixação. Os resultados mostraram que todos os participantes fixaram mais a região dos olhos de humanos e animais, sendo que o GC fixou mais tempo do que os portadores de SW e TEA. Foi possível separar usando o tempo de fixação nos olhos e HeatMaps os três grupos investigados. É viável a produção de um exame clínico auxiliar rápido e não-invasivo para indivíduos com suspeita de uma disfunção do neurodesenvolvimento. Talvez a região do nariz e boca sejam menos importantes e as orelhas mais importantes do que pensávamos nos estímulos neotênicos. Os estímulos mais neotênicos de infantes humanos e animais produziram um padrão semelhantes do tempo de fixação nos três grupos estudados. Esses resultados demonstram que portadores de SW e TEA respondem positivamente a estímulos faciais neotênicos. Sugerimos que as novas investigações na área incorporem também como variáveis faciais as orelhas, cor do cabelo e olhos, e simetria facial / Neoteny is an important biological-evolutionary process that retains phenotypic traits of the young in the adult individual of a species. Neoteny modifies the typical ontogeny velocity of the morphological characteristics shared with the ancestors. These changes may represent opportunities for dramatic phenotype modifications with few genetic changes, allowing for alterations in specialized states. The ethologist Konrad Lorenz has recognized neotenic characteristics in humans and some species of mammals in the structural formula of the body (mainly of the face) typical of infants. This body formula was named by Lorenz Kindchenschema. Typical humans respond when they observe infant traits by activating a response called the Kindchenschema Effect (KE). In this effect, there is a decrease in aggressiveness, stimulation of parental care and social engagement. There is a paucity of eye scanning in individuals with neurodevelopmental disorders such as Williams Syndrome (WS) and Autistic Spectrum Disorder (ASD). The present work is the first in the literature to investigate the eye scanning in WS and ASD patients using neotenic facial stimuli of humans and animals. In the present investigation, 21 WS and 25 ASD participants were studied. The control group (CG) had 33 participants. We found a correspondence between the stated results of the preferred stimulus and the fixation time. The results showed that all the participants fixed more the region of the eyes of humans and animals, and the CG fixed more time than the WS and ASD participants. It was possible to distinguish, using the fixation time in the eyes and Heat Maps, the three groups. The production of a rapid and non-invasive auxiliary clinical examination is feasible for individuals suspected in presenting a neurodevelopmental dysfunction. Perhaps the nose and mouth areas are less important, and the ears are more important than previously considered with respect. The more neotenic stimuli of human and animal infants produced a similar pattern of fixation time in the three groups studied. This may represent a greater adaptive value than we thought of those with WS and ASD. We suggest that the new investigations can also incorporate facial variables as ears, hair color and eyes, and facial symmetry
29

Investigação experimental do Kindchenschema lorenziano: Preferência visual de portadores de Síndrome de Williams e Transtorno do Espectro Autista em resposta a imagens neotênicas faciais / Experimental investigation of the lorenzian Kindchenschema: visual preference of Williams Syndrome patients and Autistic Spectrum Disorder in response to neotenic facial images

André Paulo Correa de Carvalho 11 December 2018 (has links)
A neotenia é um importante processo biológico-evolutivo que conserva traços fenotípicos do jovem no indivíduo adulto. A neotenia modifica a velocidade típica da ontogênese das características morfológicas compartilhadas pelos ancestrais. Essas mudanças podem representar oportunidades de mudanças fenotípicas dramáticas com poucas alterações genéticas, possibilitando alterações de estados especializados. O etólogo Konrad Lorenz reconheceu características neotênicas em humanos e algumas espécies de mamíferos na fórmula estrutural do corpo (principalmente da face) típica de infantes. Essa fórmula corpórea foi batizada por Lorenz de Kindchenschema. Os humanos típicos respondem quando observam traços infantis ativando uma resposta chamada de Efeito Kindchenschema (EK). Neste efeito verifica-se uma diminuição da agressividade, estimulação do cuidado parental e engajamento social. São raros os trabalhos de escaneamento do olhar em portadores de disfunções do neurodesenvolvimento, como a Síndrome de Williams (SW) e o Transtorno do Espectro Autista (TEA). O presente trabalho é o primeiro na literatura a investigar o escaneamento do olhar em portadores de SW e TEA usando estímulos faciais neotênicos de humanos e animais. Na presente investigação foram estudados 21 portadores de SW e 25 portadores de TEA, o grupo controle (GC) contou com 33 participantes. Encontramos uma correspondência entre os resultados declarados do estímulo preferido e o tempo de fixação. Os resultados mostraram que todos os participantes fixaram mais a região dos olhos de humanos e animais, sendo que o GC fixou mais tempo do que os portadores de SW e TEA. Foi possível separar usando o tempo de fixação nos olhos e HeatMaps os três grupos investigados. É viável a produção de um exame clínico auxiliar rápido e não-invasivo para indivíduos com suspeita de uma disfunção do neurodesenvolvimento. Talvez a região do nariz e boca sejam menos importantes e as orelhas mais importantes do que pensávamos nos estímulos neotênicos. Os estímulos mais neotênicos de infantes humanos e animais produziram um padrão semelhantes do tempo de fixação nos três grupos estudados. Esses resultados demonstram que portadores de SW e TEA respondem positivamente a estímulos faciais neotênicos. Sugerimos que as novas investigações na área incorporem também como variáveis faciais as orelhas, cor do cabelo e olhos, e simetria facial / Neoteny is an important biological-evolutionary process that retains phenotypic traits of the young in the adult individual of a species. Neoteny modifies the typical ontogeny velocity of the morphological characteristics shared with the ancestors. These changes may represent opportunities for dramatic phenotype modifications with few genetic changes, allowing for alterations in specialized states. The ethologist Konrad Lorenz has recognized neotenic characteristics in humans and some species of mammals in the structural formula of the body (mainly of the face) typical of infants. This body formula was named by Lorenz Kindchenschema. Typical humans respond when they observe infant traits by activating a response called the Kindchenschema Effect (KE). In this effect, there is a decrease in aggressiveness, stimulation of parental care and social engagement. There is a paucity of eye scanning in individuals with neurodevelopmental disorders such as Williams Syndrome (WS) and Autistic Spectrum Disorder (ASD). The present work is the first in the literature to investigate the eye scanning in WS and ASD patients using neotenic facial stimuli of humans and animals. In the present investigation, 21 WS and 25 ASD participants were studied. The control group (CG) had 33 participants. We found a correspondence between the stated results of the preferred stimulus and the fixation time. The results showed that all the participants fixed more the region of the eyes of humans and animals, and the CG fixed more time than the WS and ASD participants. It was possible to distinguish, using the fixation time in the eyes and Heat Maps, the three groups. The production of a rapid and non-invasive auxiliary clinical examination is feasible for individuals suspected in presenting a neurodevelopmental dysfunction. Perhaps the nose and mouth areas are less important, and the ears are more important than previously considered with respect. The more neotenic stimuli of human and animal infants produced a similar pattern of fixation time in the three groups studied. This may represent a greater adaptive value than we thought of those with WS and ASD. We suggest that the new investigations can also incorporate facial variables as ears, hair color and eyes, and facial symmetry
30

Eye Gaze and Cortisol Levels in Socially Anxious Young Adults During an Interactive Real World Task

Colson, Chelsea M. 01 May 2018 (has links)
Social anxiety is a disorder where people fear social interactions and is associated with physiological changes. Eye tracking studies have shown that people with social anxiety spent more time gazing at emotional faces presented on a computer screen and spent more time gazing at the eye region. There has been limited studies on tracking eye gaze in a real-life setting interacting with another person. We used a wearable eye tracker during a brief one-on-one interview about participants’ challenges faced at work or school. Along with self-report psychological measures about social anxiety and shyness, we also measured participants’ salivary cortisol as a metric for physiological stress. We hypothesized that socially anxious individuals would have higher cortisol levels and spent more time gazing at the face. However, there was no change in cortisol levels before and after the interview. In addition, socially anxious individuals had lower cortisol levels than less anxious people. Furthermore, the time spent fixating on the region of interest (ROI), which was the face, was not correlated with social anxiety, anxiety or shyness. Paradoxically, the more socially anxious participants seem to have had a lower physiological stress response than less socially anxious participants.

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